【正文】 re processors, the performance increase than 2 times greater than before, the munication speed of the bus more than three times the work data — 11 — transmission speed of 10,100,1000 Mb / s, the munications distance up to 20 km, I / O points up to 20,000 more, with the same scale system cheaper than the previous 30 to 40 percent. (4) Enhanced batch processing capacity Early DCS mainly used for process control, DCS batch processing function has continually increased, and more and show its importance. DCS use menu operation and fill in the blank approach to system configuration and graphics features are suitable for batch processing applications. DCS vast majority of new products use the same controller can achieve continuous and batch process control. DCS logic operation in the software, such as Boolean functions more functions, enhanced Sequence Control System and volume control. If ABBBailey INFI 90 system uses a batchprocessing language Batch 90 automatic processing of documents and internal Chaxi capacity, and function codes, ladder diagram mixed use, it can be directly read and write functional code and ladder diagram, allowing the interlock logic Disconnect in the order of control logic for implementation, simplifies the batch processing logic implementation. (5) software greatly enriched, an increase of senior control In the operating system, Windows NT and Unix open systems as a representative of a broad development prospects, its features include multiuser, multitasking, good character and can be transplanted working capabilities. At present, realtime industrial automation in the Unix process control system of the openness of the structure play an important role, with the exception of DCS manufacturers for the development of their own operating systems, Unix and Windows NT are in a variety of DCS in the most widely used standard operating system. DCS configuration software modules used for the objectoriented language and the language of some system uses advanced programming language and graphics software. Configuration process normally use input and output, selection, calculation, logic, the police, limit the rate of order and control modules such as soft connections, a different control loop. Menu and fill in the blankcontrol operation makes configuration very easy. DCS control algorithm is continuously improve and develop. Apart from achieving PID, nonlinear, feedforward, Cascade, feedforward and feedback, but also the sequence — 12 — control logic control and the ladder diagram, and the selftuning PID parameters set, adaptive control. DCS manufacturers for the provision of various software modules, such as SPC / SQC (statisticalprocess control / statistical qualitycontrol), CAD, artificial intelligence and expert systems, greatly enriched the DCS software library, an increase of highlevel control system , the senior now on the market has reached thousands of control packages. Expert System, multivariable predictive control, fuzzy logic control and artificial neural work technology has been gradually practical and mercialization. DCS future software design and development will continue to focus on the following several aspects of the characteristics: modular program design, objectoriented programming。 Foxbro panies addition to its own digital equipment integrated into the scene intelligent I / O system, also provides more than 60 other manufacturers, connecting doors connector. Fieldbus standard, from the bottomup equipment to achieve the interconnection of different manufacturers, with the current technology development trend. At present, the development of fieldbus standard has been a high degree of international attention, is integrated industrial automation control system indispensable ponent. With the — 13 — standardization of fieldbus munication technology development, the more intelligent DCS and control will shift downward, decentralized control equipment at the field level. They will DCS in the diagnosis and treatment provide a better platform, which enables more advanced DCS to open forms. (7) DCS further acmodate industrial PC and PLC Industrial PC and PLC equipment as the DCS is now very mon. DCS overwhelming majority of manufacturers has been providing industrial PC, PLC to DCS work connected to the hardware interface and application software. Industrial PC can make use of touchscreen and CRT window, a menudriven approach may be to establish control strategy can also be used to achieve a plug on the motherboard and external munication. Through appropriate software and hardware interfaces, industrial PC with DCS in the process of connecting loop controller for loop control graphics. DCS industrial use as a PC operating station, programming terminals, surveillance, Taiwan, workstations, such as ABBPele, panies such as DCS Feixieer few years ago and the IBM PC patible, DEC Professional, as well as 300 personal puters, etc. used for system configuration, monitoring, programming, and other tasks. Apart from some manufacturers developed a series of interface ponents and software, industrial PC as a DCS operator stations and other tasks, but also by thirdparty manufacturers such as OnSpec, and other process control packages. The relationship between the PLC and DCS is not only bine, and pete. Most are now bining DCS ladder logic programming technology, all PLC increases the simulation module to deal with the continuous production process. PLC through structural improvements, munications and working capacity and control functions to increase and the introduction of similar DCS operator station, with monitoring puter operator interface. DCS also continuously enhance and batch processing capabilities, a smallscale, highfunctional, modular direction. Thus DCS and PLC are